Drift Tengoku — September 2004 · Page 51
Page 51 — English translation
...electrode wear also weakens the spark. Waiting until a vehicle inspection to change plugs is unwise; Yamaji considers even a 3,000 km replacement interval reasonable. A plug change once restored 15 PS. Oil management matters too. Expensive oil is not automatically sufficient: some high detergent oils lose performance quickly, so extending replacement intervals can harm the engine and ultimately lead to compression loss and lower output...
...restrict the outlet to reduce noise. A wide main pipe cannot overcome a narrow exit. An efficient exhaust has few bends and a generous diameter.
Yamaji disagrees with the claim that a large exhaust necessarily loses low rpm torque. For intercoolers, wider internal passages reduce pressure loss and improve efficiency. He recommends ARC: more expensive than typical kits, but worthwhile.
Efficient supporting parts let the ECU tune move toward more power.
Captions and page details
Summit Racing strongly recommends regular spark plug replacement. Replacing plugs used for over three months has sometimes restored more than 15 PS. Fine electrode plugs can lose spark strength as they deteriorate...
Poor tuning and inadequate maintenance directly reduce power! Losing to a car with the same turbo is frustrating. Why can matching specifications give different output? There are two main reasons...
Specification
...first, ECU tuning. Expensive hardware means little if the ECU is not properly calibrated. If identical specifications produce drastically different output, suspect the tuning...
...loss.
In other words, a tuned car can produce more power...
...the second reason is insufficient maintenance. A modified car needs more attention than an ordinary one. Spark plugs are a prime example. Their noise suppressing resistors can increase resistance with use, weakening the spark and reducing output.
2
...but only if it receives frequent maintenance. Keep that in mind, or the money spent on tuning is wasted.
The shortcut to power is choosing efficient parts. Which turbo and supporting components are needed for 400 PS...
...have been covered widely in magazines. Yamaji's key point is to choose well performing parts even if they cost a little more. Most aftermarket exhausts have 76 or 80 mm main pipes, but many silencers...
400 PS varies with temperature, weather and measuring equipment
...are already widely explained.
Even among '400 PS' cars, dyno measured output and output estimated from...
...and a car estimated at 400 PS from airflow meter voltage and fuel injection can actually outrun one that measured 400 PS on a dyno...
Dyno manufacturers also differ in how high or low their results read...
...can differ.
...and temperature and weather affect output. A car that previously made 400 PS may read 380 PS next time. The number alone does not make the true comparison straightforward.
A car measuring 400 PS elsewhere may measure less than 400 here...
...at our shop we would call it below 400 PS, while the shop whose dyno recorded 400 would call it 400. The attraction of the number is understandable, but treat it as a guide.
Air filters include stainless mesh, cotton and foam types. Yamaji considers stainless mesh the most efficient for intake flow.
R
Summit Racing uses a Dynapack, which tends to read lower than roller chassis dynos. The article says power calculated from airflow meter voltage and fuel injection corresponds approximately to Bosch chassis dyno figures.
Three rules
Yamaji's three rules against power loss: 1. If identical specifications give very different output, review ECU tuning. 2. If power begins to fall, replace the spark plugs. 3. To increase power, use efficient components that expand tuning possibilities.
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6-9-24 Fukuda, Yamato, Kanagawa. Tel: 046-267-5191
Assistance: Summit Racing
About this issue
ドリフト天国 (Drift Tengoku), September 2004, is a Japanese drifting magazine. This archive preserves 316 scanned pages in their original right-to-left reading order, including the covers.
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